Wendy has taught high school Biology and has a master's degree in education.

Somatic cells are all cells in the body except germ cells, which are egg and sperm. Learn more about examples of these cells and how they differ from germ cells. Quiz your understanding at the end.

Tiny Building Blocks of Life

When we look at our bodies, it is apparent that we are made up of different parts. In a very general sense, you could say that we have arms and legs, hands and feet, a head and a torso. Taking a closer look, we can get more specific and mention our internal and external organs. We have a heart, lungs, kidney, brain, and skin, not to mention many more organs.

If we zoom in much further with the help of a microscope, we can see that all of these body parts are made of tiny building blocks called cells. In fact, every living creature is made of cells. In this lesson, we will learn about a category of cells called somatic cells. We'll gain an understanding of which cells in the body fall into this category and learn some specific examples.

Definition of Somatic Cells

All living creatures are made up of cells. In plants and animals, there are two major categories of cells: somatic cells and reproductive cells, known as germ cells or gametes. In humans and other animals, they are the egg and sperm cells.

All other cells in the body are somatic cells. Think of every body part you have; they are all made of somatic cells. The word 'somatic' is derived from the Greek word, 'soma', meaning body. You can think of soma as an abbreviation for 'so many'. This is because while germ cells include only egg and sperm, somatic cells encompass an enormous number of other types of cells.

Examples and Types of Somatic Cells

Within the broad umbrella of somatic cells, there are many differentiated types of cells that are specialized for specific areas of the body. You can imagine, knowing all the different parts that we have, all cells are not the same! Even their shape and size can vary greatly. These properties tend to vary depending on their function within the body.

Let's take a look at a specialized group of somatic cells called neurons. Neurons are nerve cells and their function is to transmit signals from the body to the brain. The physical characteristics of neurons are unique. They have a large central area called the cell body. On either side of the cell body, there are long, branched structures reaching out to receive and send the message.

It is because of these branching structures that neurons can transmit messages quickly and efficiently. They extend the length of the cell, reaching like fingers out to grab the signal and pass it on. This specialized feature allows neurons to connect our body with our brain in the most efficient way possible.

Skin cells are another example of somatic cells that have a unique property. Skin cells can regenerate themselves. Our outermost layer of skin is made mostly of dead cells that are constantly falling off. Deeper layers of skin are cell-making factories that are always replacing the dead cells. But not all types of somatic cells can accomplish this. Cells such as nerve cells cannot regenerate, and this is why a spinal injury is so devastating.

Somatic cells also include blood cells. We would not be alive without the services of blood cells. Red blood cells travel through the blood, transporting oxygen to all parts of the body and removing carbon dioxide. White blood cells, which work to fight off foreign invaders such as bacteria and viruses, keep us healthy and are a crucial part of our immune system.

Another set of highly-specialized somatic cells is found in the retina of the eyeball. These are the rod and cone cells. Rods and cones make it possible for us to see in color as well as black and white. They are found only in the eyeball and are specially adapted for this specific function.

The list of important types of somatic cells goes on and on, reflecting the diversity and specialization of these tiny building blocks. Remember, although we did not explore them all, somatic cells include all cells of the body besides the egg and sperm.

The Major Difference Between Somatic Cells and Germ Cells

If germ cells belong to one category and all other cells are somatic, you might be guessing that there is a major difference between the two types of cells, and you're right; there is. This difference lies within the nucleus of the cell. In the nucleus of every cell, there are structures called chromosomes, which are made up of genetic material called DNA.

DNA holds all of the genetic information for every living organism. Genetics has to do with the traits you inherit from your parents. Do you have red hair, perhaps like your mom? Or maybe your bright green eyes look just like your dad's. Traits like your body type, hair color, and eye color are directly related to the genetic code you received from each of your parents.

Genetic information is located on chromosomes within a cell, and this is where the major difference between somatic cells and germ cells lies. In human beings, somatic cells contain 46 chromosomes, while germ cells contain only 23 chromosomes. Why is this?

The development of a new organism begins when an egg is fertilized by a sperm. In human beings, the egg from the mother carries 23 chromosomes, and the sperm also has 23. Germ cells have half the number of chromosomes of somatic cells. When two germ cells come together, the new organism will get half of its genetic information from each parent. It will have traits from both its mother and father, and will therefore have a complete set of chromosomes (46 in the case of humans).

Lesson Summary

Somatic cells are the cells of an organism that are not germ cells, or reproductive cells. Somatic cells are highly specialized and can be very different from one another. Some examples of somatic cells include nerve cells, skin cells, and blood cells. Germ cells have half the number of chromosomes that somatic cells have.

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